title: Rationale, design and methods for a community-based study of clustering and cumulative effects of chronic disease processes and their effects on ageing: the Busselton healthy ageing study.
abstract: BACKGROUND
  The global trend of increased life expectancy and increased prevalence of chronic and degenerative diseases will impact on health systems. To identify effective intervention and prevention strategies, greater understanding of the risk factors for and cumulative effects of chronic disease processes and their effects on function and quality of life is needed.The Busselton Healthy Ageing Study aims to enhance understanding of ageing by relating the clustering and interactions of common chronic conditions in adults to function. Longitudinal (3-5 yearly) follow-up is planned.
  
  
  METHODS
  Phase I (recruitment) is a cross-sectional community-based prospective cohort study involving up to 4,000 'Baby Boomers' (born from 1946 to 1964) living in the Busselton Shire, Western Australia. The study protocol involves a detailed, self-administered health and risk factor questionnaire and a range of physical assessments including body composition and bone density measurements, cardiovascular profiling (blood pressure, ECG and brachial pulse wave velocity), retinal photography, tonometry, auto-refraction, spirometry and bronchodilator responsiveness, skin allergy prick tests, sleep apnoea screening, tympanometry and audiometry, grip strength, mobility, balance and leg extensor strength. Cognitive function and reserve, semantic memory, and pre-morbid intelligence are assessed. Participants provide a fasting blood sample for assessment of lipids, blood glucose, C-reactive protein and renal and liver function, and RNA, DNA and serum are stored. Clinically relevant results are provided to all participants. The prevalence of risk factors, symptoms and diagnosed illness will be calculated and the burden of illness will be estimated based on the observed relationships and clustering of symptoms and illness within individuals. Risk factors for combinations of illness will be compared with those for single illnesses and the relation of combinations of illness and symptoms to cognitive and physical function will be estimated.
  
  
  CONCLUSIONS
  This study will enable a thorough characterization of multiple disease processes and their risk factors within a community-based sample of individuals to determine their singular, interactive and cumulative effects on ageing. The project will provide novel cross-sectional data and establish a cohort that will be used for longitudinal analyses of the genetic, lifestyle and environmental factors that determine whether an individual ages well or with impairment.
authors.affiliation: Department of Pulmonary Physiology and Sleep Medicine/West Australian Sleep Disorders Institute, Sir Charles Gairdner Hospital, Nedlands, Perth, Australia. Alan.James.SCGH@health.wa.gov.au.
authors.forename: Alan
authors.initials: A
authors.lastname: James
authors.forename: Michael
authors.initials: M
authors.lastname: Hunter
authors.forename: Leon
authors.initials: L
authors.lastname: Straker
authors.forename: John
authors.initials: J
authors.lastname: Beilby
authors.forename: Romola
authors.initials: R
authors.lastname: Bucks
authors.forename: Tim
authors.initials: T
authors.lastname: Davis
authors.forename: Robert H
authors.initials: RH
authors.lastname: Eikelboom
authors.forename: David
authors.initials: D
authors.lastname: Hillman
authors.forename: Jennie
authors.initials: J
authors.lastname: Hui
authors.forename: Joe
authors.initials: J
authors.lastname: Hung
authors.forename: Matthew
authors.initials: M
authors.lastname: Knuiman
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
authors.forename: Robert U
authors.initials: RU
authors.lastname: Newton
authors.forename: Lyle J
authors.initials: LJ
authors.lastname: Palmer
authors.forename: Aw Bill
authors.initials: AB
authors.lastname: Musk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002908:Chronic Disease / Q000453:epidemiology / Q000517:prevention & control; D016000:Cluster Analysis; D015331:Cohort Studies; D003153:Community Health Services; D003430:Cross-Sectional Studies; D005260:Female; D006299:Health Services for the Aged; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D011788:Quality of Life; D012107:Research Design; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014904:Western Australia / Q000453:epidemiology